The present invention relates to data centers, and more specifically to data centers employing alternating coolant supply lines along cabinet rows.
The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) currently recommends that the temperature of air entering a server rack should be between 18° C. to 27° C. However, the inlet air temperature may reach up to 32° C. for short periods of time without adverse consequences.
A rear door heat exchanger (RDHx) cools exhaust air from a server rack at the rack's rear door. Coolant (i.e., chilled water) from a coolant distribution unit (CDU) enters the RDHx and is heated by the rack's exhaust air. Thus, heat from the exhaust air is transferred to the coolant. The heated coolant leaves the RDHx and returns to the CDU, where it is once again cooled. The CDU acts as a buffer between the coolant circulating in the data center and coolant used by a chiller plant.
Failure of a coolant supply line due, for example, to a coolant leak requires shutting a valve supplying coolant to the supply line. Such a failure typically results in one or more rack rows not cooling the exhaust air. In a conventional arrangement of coolant supply, a temporary coolant supply line shutdown may cause localized inlet air temperature to quickly increase beyond 32° C. Such a temperature rise may require shutdown of the electronic equipment in the rack to prevent overheating.